Humidifying unit for a hvac system

ABSTRACT

A Heating Ventilation and Air Conditioning system is provided having airways configured to direct airflow towards a confined area, the system comprising a humidifying unit having a tray disposed in the airways and configured to hold water therein, the tray is so disposed in said airways such that the water humidifies the airflow in said airways controlling thereby the humidity level in the confined area.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No. 14/897,550 filed on Dec. 10, 2015, which is a National Phase Application of PCT/IL2014/050532 filed on Jun. 12, 2014 claiming priority to U.S. Provisional Application Ser. No. 61/834,475 filed Jun. 13, 2013, U.S. Provisional Application Ser. No. 61/938,601 filed Feb. 11, 2014 and U.S. Provisional Application Ser. No. 61/969,159 filed Mar. 23, 2014. The disclosure of U.S. application Ser. No. 14/897,550 and the PCT Application are hereby incorporated by reference into the present application.

TECHNOLOGICAL FIELD

The presently disclosed subject matter, relates to a humidifying unit in general and in particular to a humidifying unit for a Heating Ventilation and Air Conditioning (hereinafter HVAC).

BACKGROUND

The presently disclosed subject matter, in some examples thereof, relates to a humidifying unit for a Heating Ventilation and Air Conditioning (HVAC) system and, more particularly, but not exclusively, to a humidifying unit that is operable to be retrofit on existing HVAC systems.

Various humidifiers have been used in the connection with home or commercial heating systems to increase the humidity level of a discharged, heated air stream. A proper humidity level in the air can enhance the comfort level of an occupant in a heated room as the moisture in the air is known to inhibit discomfort associated with undesirable drying of the nasal passages. Furthermore, the increase in air moisture enables the occupant to feel more comfortable at a lower temperature level and thereby can be used to reduce costs associated with heating.

Evaporative cooling systems that humidify circulated air are also known to be used to augment cooling provided by traditional air circulators. Some known evaporative cooling systems operate with a fluid source in combination with a powered propeller to draw an airstream through a water-soaked filter. Optionally, a separate, stand-alone pumping system is used to supply fluid to augment the cooling provided by a separate air circulator.

U.S. Pat. No. 3,855,371 entitled “Humidifying Apparatus for Warm Air Ducts and the Like,” the content of which is incorporated herein by reference describes an atomizing or spray type humidifier assembly that can be removably mounted in an air conveying duct, such as a main trunk horizontal duct, of a hot air heating system. The humidifier assembly includes a solenoid-controlled spray nozzle and a multi-layer screen supported in an elongated tunnel structure of rectangular cross-section having opposite open ends to be removably positioned wholly within the air conveying duct.

U.S. Pat. No. 4,006,674 entitled “Humidifiers for forced air systems,” the content of which is incorporated by reference herein describes a humidifier for use in forced air heating systems. The humidifier includes a housing having a water reservoir adapted to be positioned adjacent an air register, outlet, or diffuser. A duct in communication with the air register is provided within the housing for delivery of air to the water reservoir, and a flexible curtain or baffle is positioned within the housing across said duct and extending into the water of said reservoir. The arrangement requires the forced air entering the duct to flex, balloon or bow out the curtain to raise it above the water surface in order to escape to the outside. The device is adaptable to forced air floor, wall or overhead registers, outlets, or diffusers.

U.S. Pat. No. 4,741,871 entitled “Free flow humidifier,” the content of which is incorporated by reference herein describes a humidifier for use in combination with a hot air forced heating system. The humidifier consists of a main housing (water box) which maintains a constant water level from an existing water source and controlled by a float control valve. The water is heated by a hot water heating coil. Hot air is directed into, though, and back into the main hot air stream. During this process, the hot dry air picks up moisture, becoming saturated, which is returned and mixed in the hot air supply duct, providing humidity throughout the entire system. The amount of air and humidity can be controlled by the inlet dampers, which regulates the amount of air flowing through the humidifier.

U.S. Pat. No. 4,986,937 entitled “Central air duct scooper humidifier,” the content of which is incorporated herein by reference describes an ultrasonic humidifier system which is mounted to an air duct of a heating system. A vibrator excites water within a reservoir so as to create a fog within a fog chamber. A panel directs air flow from an upstream furnace into the fog chamber for interaction of the air flow with the fog. This interaction increases the moisture content of the air flow so as to increase the humidity level thereof. Reed switches are provided to preclude vibration if the level within the reservoir is low and/or if no air stream is delivered from the furnace.

U.S. Pat. No. 6,850,698 entitled “Humidifier for use with source of heated air,” the content of which is incorporated herein by reference describes a free-standing humidifier that is suitable for placement near a source of heated air. Optionally, the humidifier is placed over a floor register in a home. The humidifier has a main reservoir for holding water, a rod having a length sufficient to extend across the reservoir, and panels that support the rod. A disposable paper towel is draped over the rod and one end of the paper towel is inserted through an opening in the top of the reservoir into water in the reservoir. Air flowing from the source impinges upon the paper towel and picks up moisture from it. A supplemental reservoir can be used to automatically supply additional water to the main reservoir from a water line that has a valve controlled by a float which turns the valve on and off.

GENERAL DESCRIPTION

According to one aspect of the presently disclose subject matter there is provided a humidifying unit for a heating ventilation air conditioning (HVAC) system comprising a tray disposed at the airways of the HVAC system configured to hold water therein and for humidifying the air stream in the airways. The humidifying unit can be provided as a stand-alone apparatus for integrating in the airways of a HVAC or can be integrally formed in the airways of an HVAC system.

The humidifying unit can be configured to be integrated or installed in a ductwork of a central HVAC system or in the airways of a single room unit such as ductless system, a split-system, window air conditioner or a portable system.

The humidifying unit can be provided with a humidity level by controlling the exposure of airstream to the water in the tray control which according to an example can be in the form of a moving lid disposed over the tray.

The humidifying unit allows a passive operation of introducing humidity into the air steam of the HVAC system by utilizing the kinetics of the air stream flowing in the airways thereof.

According to an example of the presently disclosed subject matter, the humidifying unit is integrated into an air handler of a ductless HVAC unit proximal to a vent through which air stream is pushed out. The humidifying unit can include a tray, channel and/or box for holding water. The tray can be integral to a frame of the vent in the air handler through which air stream is blown out. The frame of the air handler can provide a dedicated space and/or base for positioning the humidifying unit. Optionally, frames of existing air handlers are modified to provide the dedicated space and/or base. The tray can further include one or more water inlets and/or outlets.

The humidifying unit can be operable to increase a humidity level of air stream outflow from the HVAC system during heating, ventilation and also during cooling. During heating, the hot air stream blown out of the HVAC system passes over the tray filled with water leading to evaporation. The inventor has found that since both the velocity of air flow and the temperature of the air stream is relatively high as it exits the vent, a relatively high rate of evaporation can be achieved by pacing the humidifying unit near the vent.

Optionally, while the HVAC system is operated in a cooling mode, e.g., air conditioning mode, water that is condensed during cooling is directed toward the tray and used to humidify the air stream outflow of the HVAC system. Although, the rate of evaporation is typically lower during cooling, the inventors have found that some water will be absorbed in the air stream. Optionally, while the HVAC system is operated in ventilation mode and the ventilated air is relatively warm and dry, HVAC system together with the humidifying unit can be operated as an evaporated cooling system to both cool and humidify the ventilated air.

According to another example of the presently disclosed subject matter, the humidifying unit is integrated into a grille and/or ductwork connector of a mini-duct or duct HVAC unit. The humidifying unit can include a tray for holding water that is integral to the grille or ductwork connector. As used herein the term ductwork connector refers to a part that used to connect duct tubing to a grille. The tray can include one or more water inlets and/or outlets through which tubing can be connected.

According to further examples of the presently disclosed subject matter, the humidifying unit is integrated into a main airflow duct channel of a central HVAC system and is operable to humidify the air stream outflow prior to splitting the air stream outflow to a plurality of different ducts.

According to a further aspect of the presently disclose subject matter there is provided a HVAC system having airways configured to direct airflow towards a confined area, the system comprising a humidifying unit having a tray disposed in the airways and configured to hold water therein, the tray is so disposed in said airways such that the water humidifies the airflow in said airways controlling thereby the humidity level in the confined area.

The water tray can be integrally formed with a wall portion of the airways. The airways can include a duct channel having a grille and wherein the water tray is integrally formed with said grille. The airways can include a ductwork connector and wherein the water tray is integrated therein.

The HVAC system can be a central air system having a central duct and the water tray can disposed in said duct.

The humidifying unit can include an adjusting mechanism for adjusting the surface area of the water exposed to the airflow in the airway. The adjusting mechanism can include a lid configured to be selectively disposed with respect to the tray determining thereby the surface area of the water exposed to the air in the airway.

The HVAC system can further include a controller for controlling the disposition of the lid in accordance with the desired humidity level. The HVAC system can include a water inlet line connected to the water tray via a water inlet port. The HVAC system can include a condensation drainer being configured to direct water from a condensation drain towards the tray. The controller can be operative to initiate filling of water in response to turning on of the HVAC system.

The tray can be provided with a drain line configured to drain the water inside the water tray. A controller can be provided and can be operative to initiate draining of water in the water tray in response to turning off the HVAC system.

The adjusting mechanism can include a water level regulator configured to control the water level in the water tray thereby adjusting the surface area of the water exposed to the airflow in the airway.

The HVAC system can further comprise a heating element disposed in the water tray and configured to heat the water therein thereby accelerating humidification of the air in the airways. The heating element is a heated gas line of the HVAC system directed to the water tray for heating water in the water tray.

The HVAC system can further comprise a cleaning mechanism for removing calcification accumulating therefrom. The cleaning mechanism can include a brush for breaking up calcification accumulating in the water tray. The cleaning mechanism comprising a high-pressure sprinkling rod operative to direct high-pressure water toward in surface of the water tray for breaking up calcification accumulating in the water tray. The HVAC system can further comprise a wall portion disposed inside the airways, having a surface configured to allow water flow thereon to form said tray. The wall portion can be a sloped wall and the tray can be at a top portion thereof, such that water from the tray can flow downwardly under gravitational forces towards a low portion of the wall.

The humidifying unit may be configured to have any of the following features:

-   -   a removable cover that can be partially and fully opened and/or         closed to vary the exposure of water to the air stream and         thereby alter the humidity level achieved with the humidity         unit;     -   a mechanism for tilting the tray by varying degrees, thereby         controlling the surface area of the water that comes into         contact with the airstream;     -   A humidity sensor for sensing the humidity level in a room, the         sensor being coupled to the humidifying unit which determines         the exposure area of the water inside the airways;     -   A manual or automatic mechanism for halting of the humidifying         unit when the HVAC unit is on the cooling mode thereof;     -   An adjusting mechanism for adjusting the exposure area of the         water, thereby adjusting the humidity level in the air;     -   A filling mechanism for filling the tray in response to a water         level therein below a predetermined threshold; the filing         mechanism can be in configured to collect condensed water formed         during cooling mode;     -   A draining mechanism for draining the tray in response to a         water level therein above a predetermined threshold;     -   An auxiliary reservoir being in fluid communication with the         tray and configured for despising thereto cleaning liquid;     -   The cleaning liquid can be configured to prevent bacteria         accumulation or can be a scale cleaning liquid or can include an         odor elimination material.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, examples will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

FIGS. 1A and 1B are simplified schematic drawings respectively of a known air handler for a ductless HVAC unit and the air handler with a humidifying unit in accordance with some examples of the presently disclosed subject matter;

FIG. 2 is a simplified schematic drawing of optional water supply and drainage features of a humidifying unit in an air handler of a ductless HVAC system in accordance with an example of the presently disclosed subject matter;

FIG. 3 is a simplified schematic drawing of a humidifying unit integrated into a grille extending from duct channel of an HVAC system in accordance with some examples of the presently disclosed subject matter;

FIG. 4 is a simplified schematic drawing of a humidifying unit integrated into a connector between a duct channel and grille of an HVAC system in accordance with some examples of the presently disclosed subject matter;

FIG. 5 is a simplified schematic drawing of a humidifying unit integrated with a central air HVAC system in accordance with some examples of the presently disclosed subject matter;

FIG. 6A is a simplified schematic drawing of a HVAC system having a humidifying unit in accordance with another example of the presently disclosed subject matter;

FIG. 6B is an exploded view of the HVAC system of FIG. 6A;

FIG. 6C is a side sectional view of the HVAC system of FIG. 6A;

FIG. 7A is a front perspective view of the humidifying unit of FIG. 6A;

FIG. 7B is an exploded view of the humidifying unit of FIG. 7A;

FIG. 7C is an enlarged view of the pumping mechanism of the humidifying unit of FIG. 7A;

FIG. 7D is an enlarged view of the adjusting mechanism of the humidifying unit of FIG. 7A;

FIG. 8 is a simplified schematic drawing of a humidifying unit with an optional tilting feature in accordance with some examples of the presently disclosed subject matter;

FIG. 9A is a side sectional view a folded cardboard in accordance with one example of the presently disclosed subject matter, disposed in a tray of a humidifying unit;

FIG. 9B is a side sectional view of cardboard of FIG. 9A;

FIG. 9C is a side perspective view of the tray of FIG. 9A;

FIG. 10A is a top view of a cardboard in accordance with another example of the presently disclosed subject matter;

FIG. 10B is a perspective view of a cardboard in accordance with another example of the presently disclosed subject matter;

FIG. 11A is a side sectional view of an AC unit having a humidifying unit in accordance with another example of the presently disclosed subject matter; and,

FIG. 11B is an enlarged view of the humidifying unit of FIG. 11A.

DETAILED DESCRIPTION OF EXAMPLES

Reference is now made to FIGS. 1A and 1B showing simplified schematic drawings respectively of a known air handler for a ductless HVAC system and the air handler with a humidifying unit in accordance with some examples of the presently disclosed subject matter. A known air handler and/or evaporator unit 101 of a split ductless HVAC system typically includes a vent 110 through which conditioned air, e.g., heated, cooled, or ventilated air is expelled and/or blown out. Typically, vent 110 is encompassed and/or defined by a frame 112 that is formed as part of a cover of air handler 101. Typically, an array of directional blades 115 can be controlled to direct the air expelled through vent 110 in a desired direction, e.g., left, or right. The vent 110 can be covered by a flap 120 that can be rotated to control the direction of air flow in a vertical direction, e.g., up, and down. The flap 120 can be closed while air handler 101 is not in an operational mode, e.g., while air handler 101 is switched off.

According to some examples of the presently disclosed subject matter, there is provided a humidifying unit 150 that is integrated into an air handler 105 of an HVAC system. According to some examples of the presently disclosed subject matter, humidifying unit 150 is positioned in a vent 111. Typically, frame 113 defining an extent of the vent 111 is enlarged as compared to frame 112 (FIG. 1A) to accommodate humidifying unit 150. In some examples, humidifying unit 150 is positioned below directional blades 115 and within frame 113.

According to some examples of the presently disclosed subject matter, humidifying unit 150 includes a tray and/or water box 160 for collecting and/or holding water. Optionally, tray 160 includes one or more inlet and/or outlet ports through which water and/or other fluids can be introduced and/or drained from tray 160. According to some examples of the presently disclosed subject matter, tray 160 is formed as part of frame 113. Optionally, frame 113 is formed from with a polymer material by a molding process and tray 160 is molded as part of frame 113. Alternatively tray 160 is a part distinct from frame 113 and is inserted into frame 113. According to some examples of the presently disclosed subject matter, as air outflow 180 is expelled from air handler 105, it skims the surface of water contained in tray 160 and becomes humidified, e.g., saturated with water vapor. In some examples, water supply for humidifying unit 150 is provided by a water supply tube 170 that optionally connects to a main water line or other water source, e.g., a tank. Optionally, water supply tube 170 is fitted with a safety valve 175 for cutting off water supply to tray 160. Optionally, safety valve 175 is fitted within the housing of air handler 105. Optionally, a filter is fitted in tube 170 for filtering water supply to tray 160. Optionally, tray 160 is manually filled with water.

The tray 160 can be sized to extend over a substantially entire length of vent 111 so that air outflow 180 has adequate interface with water contained in tray 160. The height of tray 160 can span between 1-5 cm and the depth of tray 160 can span between 1-5 cm, depending on dimensions of air handler 105. The tray 160 can be sized to hold approximately 100-400 ml of water. Reference is now made to FIGS. 2A and 2B, water supply tube 170 can be provided and configured to supply water to tray 160 to maintain a desired level and/or volume of water within tray 160. The water supply tube 170 can be associated with a valve 172 that can be controlled by controller 200 of humidifying unit 150 or a float valve in tray 160. The valve 172 and safety valve 175 can be integrated in a single module integral. In some examples of FIG. 2b , water from condensate drain tube 177 drains water via and/or to tray 160 so that condensate drain tube 177 can supply water to the tray 160 while the HVAC system is in a cooling mode. Optionally, a gas pipe in a condenser portion of the HVAC system is extended into tray 160 and used to warm the collected water.

The humidifying unit 150 can include a drain 175 for draining water out of tray 160. Optionally, two drains 175 on opposite sides of tray 160 are used to avoid drainage problems due to an angle in tray 160. The drain 175 can be connected with tubing 176 that typically directs condensed water formed during cooling to outside a building or home so as to allow evacuation of water from the tray. Alternatively, humidifying unit uses dedicated tubing to drain water out of tray 160 to a sewage line and/or outside a building or home. Typically drain 175 is associated with a valve 179 for controlling water flow out of drain 175 that can be operated by a controller 200 of humidifying unit 150. The humidifying unit 150 can additionally include an overflow drain (not shown) which drains into condensate drain line 176. It is appreciated that in case the HVAC system is not configured with a cooling mode, and thus does not provide condensed water, the system can be provided with a condensation apparatus, for example, from the outside ambient, so as to provide water into the tray.

It is noted that although humidifying unit 150 has been described in FIGS. 1, 2A and 2B as being integrated into a split ductless HVAC system typically including an air handler inside of a room and a compressor positioned outside, a similar construction can be used for example in a single unit air conditioner, e.g., an air conditioning window unit.

Reference is now made to FIG. 3, a humidifying unit can be integrated into a grille extending from duct channel of an HVAC system. According to some examples, the humidifying unit is integrated into ductwork of the HVAC system. A tray 260 of a humidifying unit 250 can be positioned and/or integrated onto a grille and/or register 210 positioned on a wall of a room, e.g., a wall of a dropped ceiling. As air outflow 280 blowing out from grille 210, e.g., in a generally horizontal direction it skims the surface of water contained in a tray 260 of humidifying unit 250 and becomes humidified, e.g., saturated with water vapor. In some examples, tray 260 is integral to grille 210 and includes one or more water outlet and/or inlet ports for receiving and/or draining water into tray 260. Optionally, grille 210 is molded with a cavity defining tray 260. Optionally, a depth of grille 210, e.g., its dimension going into the wall is increased relative to known dimensions of grilles to accommodate tray 260. Optionally, tray 260 is a separate part that is fastened onto grille 210 during manufacturing. Typically tray 260 extends over a length of a vent opening of grille 210 and is typically interior to direction blades of grille 210 so that it is concealed. In some examples, both height depth of tray 260 ranges between 0.5-3 cm, although dimensions of tray 260 typically vary with size of grille 210. Optionally, for ceiling grilles, tray 160 is integrated into the direction blades of the grille.

The water supply to tray 260 can be provided by a water line 270. Optionally water line 270 connects to a water source, e.g., a main water line and water line 270 that extends through duct tubing 220 to tray 260. Alternatively, water line 270 can be positioned outside of duct tubing 220 and is connected to tray 260 via a port in tray 260 (not shown). The water can be filled by manually filing tray 260. According to some examples of the presently disclosed subject matter, a drain 275 with drain line 282 connects to tray 260 for draining water from the tray when required. Typically, drain 275 with drain line 282 is associated with a valve for controlling draining. Optionally, drain line 282 is directed toward a sewage line of the premises or is otherwise drained outdoors. Optional features of humidifying unit 250 are described in more details herein in reference to FIGS. 6-8.

Reference is now made to FIG. 4 showing a humidifying unit 350 integrated into a connector between a duct channel and grille of an HVAC system in accordance with some examples of the presently disclosed subject matter. The tray 360 of a humidifying unit 350 is positioned and/or integrated into a ductwork connector 310 between a duct channel 320 and grille 310 of an HVAC system, where at least a portion of the ductwork connector is positioned horizontally, e.g., parallel to a dropped ceiling. Optionally, grille 310 is a wall grilled. Alternatively, a ceiling grille that directs air flow from a generally horizontal duct channel 320 downwards in a generally vertical direction is used.

Typically, tray 360 is positioned so that walls of the tray do not obstruct air flow 380 blowing through connector 310. Optionally, walls of tray 360 are insulated to avoid condensation on outer walls. As air outflow 380 blows out through grille 310 in a horizontal direction it skims the surface of water contained in tray 360 of a humidifying unit 350 and becomes humidified, e.g., saturated with water vapor. The tray 360 can be integral to connector 310 and includes water outlet and/or inlet ports for receiving and draining water into tray 360. Optionally, connector 310 is molded with a cavity defining tray 360. Optionally, tray 360 is a separate part that is fastened onto connector 310 during manufacturing and/or assembly. Optionally, tray 360 is sized to substantially extend over a diameter of duct tubing 320. Optionally, tray 360 is sized to substantially extend over a length of connector 310. Optionally, the depth of tray ranges between 1-5 cm although its depth will typically vary with different sizes of duct connectors and/or duct tubing and can be deeper than 5 cm.

The water supply to tray 360 can be provided by a water line 370. Optionally water line 370 connects to a water source, e.g., a main water line and water line 370 extends through duct tubing 320 to tray 360. Alternatively, water line 370 is positioned outside of duct tubing 320 and is connected to tray 360 via a port in tray 360 (not shown). in addition, a drain 375 can be provided and can include drain line 382 connected to tray 360 for draining water from the tray when required. Typically, drain 375 with drain line 382 is associated with a valve for controlling draining. Optionally, drain line 382 is directed toward a sewage line of the premises or is otherwise drained outdoors. Optional features of humidifying unit 350 are described in more details herein in reference to FIGS. 6-8.

Reference is now made to FIG. 5 showing a simplified schematic drawing of a humidifying unit 450 integrated with a central air HVAC system in accordance with some examples of the presently disclosed subject matter. A tray 460 of a humidifying unit 450 is positioned and/or integrated onto a main duct line 420 of the central HAVC system prior to the air flow splitting into plurality of duct lines 421, 422, 423 and 424. Optionally, tray 460 is sized to substantially extend over a diameter of main duct tubing 420. A water supply to tray 460 can be provided by a water line 470 and is drained with a drain line 482. Optional features of humidifying unit 450 are described in more details herein in reference to FIGS. 6-8.

Reference is now made to FIG. 6, a humidifying unit 550 can be integrated in a wall mounted AC unit 500 having a cooling unit 510 and a cover 512 defining an air outlet aperture 514. As sown in FIGS. 7A and 7B, the humidifying unit 550 includes a tray 560 and a pumping mechanism 570 for supplying the tray 560 with water. The pumping mechanism 570 can be configured to pump water from a reservoir 555 coupled to the AC unit 500.

As shown in FIG. 7C the pumping mechanism 570 can include a pump 572 which is configured to pump liquid, such as water, form the reservoir 555. According to the illustrated example the pump 572 is coupled to an auxiliary reservoir 574 via a pipe 575, which can include a cleaning liquid, and which is coupled to the reservoir 555. This way, the pump draws water from the reservoir 555 as well as cleaning liquid from the auxiliary reservoir 574. The cleaning liquid can be any known liquid configured to prevent bacteria accumulation inside the tray 560, or can be a scale cleaning liquid, or odor elimination material. In addition, the cleaning liquid can include other additives for purifying the air in the room, smell additives, or other chemicals which it is desired to spray in the room.

It is appreciated that the tray can be provided with a sensor for sensing the quality of the water therein, such that the pump can be activated to draw cleaning liquid from the auxiliary reservoir 574 in response to low quality water in the tray.

According to an example the tray can be removable tray such that it can be periodically removed and cleaned.

According to an example, the tray can be formed form a scale resistant material. It is appreciated that according to an example the tray can be disposed with respect to the airflow, such that dust in the air can be collected by the water surface, such that the water facilitates in cleaning the air.

According to an example the pump is coupled to an electric valve 578 which is configured to provide water to a dripper element 580. The dripper element 580 is configured to release a small stream of water, or drips of water into the tray 560. The electric valve 578 can be configured to control the operation of the pump and to dictate the amount of cleaning liquid which is released. The pumping mechanism 570 can be encased in a housing 582 provided with a door 584.

According to an example, the pumping mechanism 570 further includes a draining pump 576, coupled to the tray 560 via a pipe 562. The draining pump is configured to draining the water in the tray, and it can be coupled to a sewage system, or can be coupled to a pipe which can be used to direct the drained fluid into a bowl upon the need. The draining pump can be activated to drain water from the tray, when the temperature of the water rises above a predetermined threshold, for example to a level which does not allow proper humidification of the airstream. In the latter case the pumping mechanism 570 can be configured to provide fresh water to the tray so as to allow continuous humidification of the airstream.

The tray 560 can be provided with an adjusting mechanism for adjusting the exposure area of the water, thereby adjusting the humidity level in the air. The adjusting mechanism can include removable lid 505 configured to selectively open and close in response to the humidity level in the room. The removable lid can be provided with an actuating mechanism 530.

Reference is now made to FIG. 7D, the actuating mechanism 530 can include a motor 531 having a cogwheel 532 mounted thereon configured to engage a corresponding cogwheel 524 on which the lid 505 is mounted. When the motor 531 is activated the cogwheel 532 is rotated in one direction causing the corresponding cogwheel 524 and the lid 505 to turn in the opposite direction. The lid 505 according to this example is configured as a semi-circular cover, such that in response to rotation of corresponding cogwheel 524 the lid 505 rotated about the tray 560. This way, the disposition of the lid 505 with reference to the tray 560 can be determined and so does the surface area of the water which is exposed to the air in the airway of the AC unit.

It is appreciated that the corresponding cogwheel 524 can defined teeth 526 only about a portion of the circumference thereof. This way when the motor 531 is rotated and the teeth of the cogwheel 532 engage teeth 526, the corresponding cogwheel 524 and the lid 505 are rotated as well. As the teeth of the cogwheel 532 reach the area on the circumference of the corresponding cogwheel 524 which does not include teeth the rotation of the corresponding cogwheel 524 and the lid 505 stops. Thus, the amount of teeth on the corresponding cogwheel 524 determines the maximum rotation of the lid 505, and precludes damage thereto, when fully closed or fully opened.

In some examples, a heating element (not shown) is introduced into tray 560 for heating and/or sterilizing water in the tray. Optionally, the heating element can be operated to boost evaporation of water in tray 560. The tray 560 can be fitted with a removable lid 505. The humidity level provided by the humidifying unit can be controlled by controlling position of removable lid 505. The controller can be configured to partially close removable lid 505 to reduce the humidity level provided by humidifier 550. Optionally the controller can fully close the removable lid 505 while the AC unit 500 is not operated, e.g., is turned OFF so that the water and/or tray remains clean while not being used. Optionally, a humidity sensor (not shown), e.g., a hygrometer is used to detect a humidity level in room and to provide input to controller for controlling a humidity level provided by humidifying unit 550. The humidity sensor can be positioned in an air handler, near a thermostat of the AC unit 500 and/or anywhere in a room that is being heated or cooled.

According to another example the adjusting mechanism can include a water level regulator configured to sense and control the water level in the water tray thereby adjusting the surface area of the water exposed to the airflow in the airway.

The tray 560 can be installed with one or more mechanisms for breaking up calcification that can accumulate on inner surfaces of tray 560. Optionally, a brush (not shown) can be provided for removing scale from the tray and can be disposed in the tray such that it touches the floor thereof. The brush can be operated with a piezoelectric element that vibrates and/or motor that moves brush so that it breaks up accumulated calcification. Alternatively, a high-pressure sprinkling rod can be fluidly connected to a water supply line and high pressurized water expelled from a sprinkling rod provides for breaking up accumulated calcification, on walls and floor of tray 560. The tray 560 is installed with a basket (not shown) that is operable to hold a tablet for softening, disinfecting and/or adding fragrance to the water in tank 560. Optionally, the basket can include a removable cover that can be used controllably expose the basket to water in tank 560.

The tray can further be provided with means for stirring the water, for example a small turbine coupled to a motor, a flow generator inside the tray, or a pump, this way the top surface of the water is constantly stirred, and the heating of the water surface is mitigated. It is appreciated that maintaining the temperature of the water surface below a certain threshold can help the humidifying process of the airstream. The turbine can be activated only in response to a rise in the temperature of the water surface in the tray. According to another example the turbine can be activated so as to reduce the evaporation of the water in the tray.

A draining pump 576 can be provided and can be operable to initiate draining of tray 560 in response to sensing that theca unit has been turned off. Optionally, the controller is operable to initiate cleaning of tray 560 with the brush and/or sprinkler rod in response to sensing that the AC unit 500 has been turned off. Optionally, controller is operable to initiate filling of tray 560 with water in response to detecting that the systemic unit has been turned on and/or in response to input from a humidity sensor. Optionally, the tray is slanted so that calcification is localized near drain.

According to some examples of the presently disclosed subject matter, the cover can be rounded and can be formed from one or more blades that can be collapsed to open cover to varying extents, e.g., partially, or fully.

Reference is now made to FIG. 8 showing a tray 560 in accordance with another example. The tray 560 is supported with by an axle 513 that can be rotated to tile tray 560 to a desired angle. Optionally, a motor communicates with axle 513 for rotating the axle. Optionally, different tilt angles are used to control the humidity level provided by humidifying unit 550. Optionally, tilting tray 560 provides for changing the surface area of the water in tray 560 and thereby changing humidity level provided by humidifying unit 550. Typically, a larger surface area provides increased humidity while a smaller surface area provides decreased humidity. Optionally, tilting tray 560 away from air flow reduces the humidity level provided or stops the humidifying action while tilting tray 560 toward the air flow increases the humidity level provided by humidifying unit 550. Optionally, the tilting feature is used in place of the lid. In the previous examples the humidifying systems is configured to provide a contact between the passing air and a surface of water disposed inside the ventilation system thereby humidifying the air. It will be appreciated however, that the amount of moisture transferred from the water to the air is proportional to the area of contact surface between the air and the water. Accordingly, in order to achieve sufficient air humidity in the room, the contact area can be increased, beyond the dimensions of the tray of the humidifying systems.

According to an example increasing the surface area can be carried out by utilizing a porous hydrophilic material, such as a cardboard, for significant increase of the contact area of passing air with water.

Reference is now made to FIG. 9A, a tray 605 can be configured to hold water 606 therein, together with a folded cardboard 600. The cardboard 600 is configured to absorb water 606 therein, and due to the folding thereof it can define a large surface area, thus increasing the surface area of water particles with the air. It is appreciated that folding of the cardboard 600 is configured such that on one hand water can be absorbed therein and on the other hand air form the HVAC system can flow through the gaps 607 formed between the folds. The cardboard 600 can be disposed inside the tray 605 such that the folds are perpendicular to the direction of the airflow in the HVAC system, such that the air flows through the gaps 607 formed therebetween.

To improve water transfer, a variety of cardboard can be selected having wetting ability and at the same time maintaining rigidity in wet condition. It is also possible to add a certain detergent to the water, which would increase the wetting and improve the transfer of moisture.

As shown in FIG. 9B, the cardboard 600 can includes an inner layer 602, and outer layer 604 and a corrugated layer 603 disposed therebetween configured to provide capillary water transfer therethrough.

According to another example, as shown in FIG. 10A, the cardboard 630 can be provided with a plurality of apertures 635, such that air can flow therein contacting thereby more surfaces of cardboard and accumulating humidity thereby.

According to a further example, as shown in FIG. 10B, the cardboard 640 can be provided with a plurality of apertures 642, provided at the top portioned of each fold such that air can flow through the top portion of the cardboard 640, contacting thereby more surfaces of cardboard and accumulating humidity thereby.

It is appreciated that other techniques form improving humidifying of the water can be utilized such as heating and evaporating portion of water or applying ultrasound waves for forming water particles.

The tray according to other examples can be filled with ice powder or pulverized or powder-like ice can also cool air.

As shown in FIGS. 11A and 11B, according with a further example an AC unit 670 can be provided with a humidifying unit 680 configured to provide fluids flow, such as water, along a wall 682 disposed inside the air duct. The wall 682, here illustrated as sloped wall can alternatively be a vertical or a, such that water provided on a top portion thereof, flow downwardly under gravitational forces towards a low portion thereof. It is appreciated that the wall 682 can be one of the inner walls of the airway of the AC unit.

The water can be provided on the wall 682 by forming a water channel 681 at the top portion of the wall 682. The channel 681 is configured such that when water therein overflow, the water spill onto the wall downwardly. This way, the exposure area of the air to the water is not only the area of the tray, rather it is the area of the wall 682 on which water are provided.

Thus, the channel 681 can be defined along the entire length of a wall portion which in the airway of the AC unit, such that all the air flowing inside the AC unit is exposed to the water on the wall and humidity is accumulated in the air. The level in the water tray can be maintained such that water overflow towards the wall when the humidity level of the room falls below the desired level. This can be carried out for example by providing a tray 685 having water 675 therein, and a pump 690 providing fluid communication between the tray 685 and the channel 681 by means of pipe segments 692 a and 692 b. The pump 690 can be configured to pump water onto the channel 681 when the humidity level drops below the desired level.

The humidifying unit 680 can further be provided with a draining mechanism for draining any redundant water at the bottom of the wall portion 682. According to the illustrated example the draining mechanism is a slit 695 defined along the length of the wall, underneath which the tray 685 is disposed.

According to an example, the humidifying unit can be a slit 695 provided with water therein, for example by disposing a water tray underneath. The slit 695 can be disposed along the entire width of the airway, and the can disposed at the bottom of the wall portion 682, or along nay other point of the wall portion, which is illustrated here as a sloped wall portion. It is appreciated that according to this example, the wall portion 682 is not configured to allow water flow thereon, rather the inventor has found that defining a slit 695, or a similar channel on the sloped wall or at the bottom thereof, enhances the humidification process.

It is appreciated that the humidifying unit of the presently disclosed subject matter substantially does not consume energy however merely operate by utilizing the kinetics of the air stream flowing in the airways thereof. The humidifying unit can be provided with an energy source for operating the adjusting mechanism and such that the disposition of the cover is manipulated, or for operating the pump providing the water into the tray.

It is appreciated that in addition, to the above, utilizing the humidifying unit substantially eliminate the need to open the window so as to adjust the humidity level in the room, thus the presently disclosed humidifying unit reduces the energy consumption of the HVAC system.

When hot air flows through the air duct, the water along the wall raise the humidity level of the air.

It is appreciated that the dimensions of the wall, such as the length and the width thereof determine the exposure of the air inside the air duct to the water, and the humidity formed thereby.

According to an example the wall can be a horizontal wall, the water can be provided on one side thereof by sprinklers, the airflow urges the water to flow along the wall.

According to other examples, the water can be provided by means of sprinkles configured to sprinkle water on the top of the wall, thereby causing the water to flow downwardly.

It is noted that although most of the examples of the presently disclosed subject matter have been discussed in reference to home and/or building HVAC systems, the humidifying units described herein can also be used and/or adapted for use in HVAC systems in vehicles, such as cars, trains, busses, and aircrafts.

In addition, the humidifying units can be integrated in any A/C system such as air curtains, air conditionings, evaporative Cooling Units, and humidifiers. Etc. The terms: “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean “including but not limited to.”

As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof.

It is appreciated that certain features of the subject matter, which are, for clarity, described in the context of separate examples, may also be provided in combination in a single embodiment. Conversely, various features of the subject matter, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the subject matter. Certain features described in the context of various examples are not to be considered essential features of those examples unless the embodiment is inoperative without those elements. 

1. A humidifying unit for a heating ventilation air conditioning (HVAC) system, comprising: a tray configured to be disposed at airways of the HVAC system and configured to hold water so as to humidify an air stream in the airways; and one or more mechanisms configured to increase and decrease contact area between the water and the air stream in the airways.
 2. The humidifying unit according to claim 1, wherein the tray is integrally formed with a grille of a duct channel of the HVAC system.
 3. The humidifying unit according to claim 1, the one or more mechanisms comprising a lid configured to be selectively disposed with respect to the tray, the lid being configured to increase and decrease the contact area between the water and the air stream in the airways.
 4. The humidifying unit according to claim 3, further comprising a controller for controlling the disposition of the lid in accordance with a desired humidity level.
 5. The humidifying unit according to claim 1, further comprising a heating element disposed in the tray and configured to heat the water therein thereby accelerating humidification of the air stream in the airways of the HVAC system.
 6. The humidifying unit according to claim 5, wherein said heating element is a heated gas line of the HVAC system directed to the tray for heating water in the tray.
 7. The humidifying unit according to claim 1, further comprising a basket operative to hold a tablet in fluid communication with water in the tray for disinfecting or softening the water in the tray.
 8. The humidifying unit according to claim 1, wherein the one or more mechanisms include a tilting mechanism comprising an axle, wherein the tray is supported on the axle of the tilting mechanism, and wherein the axle is configured to be rotated for tilting the tray.
 9. The humidifying unit according to claim 1, wherein the tray further comprises folded surfaces comprising hydrophilic cardboard comprising a corrugated layer, the corrugated layer configured to provide capillary water transfer.
 10. A heating ventilation air conditioning (HVAC) system having airways configured to direct airflow towards a confined area, the HVAC system comprising a humidifying unit comprising a tray disposed in airways and configured to hold water therein, the tray is so disposed in said airways such that the water humidifies an airflow in said airways thereby controlling humidity level in the confined area, said humidifying unit further having one or more mechanisms configured to increase and decrease contact area between the water and the airflow in the airways.
 11. The HVAC system according to claim 10, wherein the tray is integrally formed with a wall portion of the airways.
 12. The HVAC system according to claim 10, wherein the HVAC system is a central air system having a central duct and wherein said tray is disposed in said duct.
 13. The HVAC system according to claim 10, further comprising a water inlet line connected to the tray via a water inlet port.
 14. The HVAC system according to claim 10, wherein said tray is provided with a drain line configured to drain the water inside the tray.
 15. The HVAC system according to claim 10, further comprising a heating element disposed in the tray and configured to heat the water therein thereby accelerating humidification of the airflow in the airways.
 16. The HVAC system according to claim 10, further comprising a cleaning mechanism for removing calcification accumulating in the tray.
 17. The HVAC system according to claim 10, further comprising an auxiliary reservoir in fluid communication with the tray and configured for dispensing a cleaning liquid to the tray.
 18. The HVAC system according to claim 10, further comprising a wall portion disposed inside said airways, the wall portion having a surface configured to allow water flow thereon from said tray.
 19. A method for humidifying air directed out of a heating ventilation air conditioning (HVAC) system to a confined area, the method comprising: disposing a water tray inside airways of the HVAC system such that water therein humidifies an airflow in said airways thereby controlling humidity level in the confined area; and forming one or more mechanisms for increasing and decreasing contact area between the water and the airflow in the airways. 